玉米雄性不育基因MS305的功能及调控网络研究

玉米作为我们的主要粮食作物，在保障我国粮食安全上发挥的重要作用。开展控制雄穗发育和雄性育性的重要基因的功能和调控网络的研究，具有重要意义。ms305是玉米中一个新的雄性不育突变体。ms305纯合突变体的株型和生育期与野生型基本一致，但其花药不能外露，内部花粉败育。BSA测序分析和CRISPR/Cas9敲除实验确定，该基因编码一个脱水蛋白。突变体中在一个保守结构域区段内的一个碱基的替换（G>A）造成了一个氨基酸的变化，最终导致了ms305突变体的表型。本项目将进一步结合转录组学、基因编辑技术以及多种生化方法等，研究MS305基因的表达调控网络、互作蛋白和该基因的潜在DNA结合位点以及MS305基因的逆境胁迫响应模式。本研究不仅将解析MS305控制玉米雄穗育性的分子机制和其遗传调控网络，揭示其在响应逆境胁迫的作用，还为新型核雄性不育系的开发提供新的基因资源。

Maize is a major crop, playing critical role in contributing to the food security in China. Understanding the molecular mechanism of tassel development and nuclear gene controlled male sterility is of importance in maize. ms305 is a newly identified male-sterile mutant. Phenotype analysis showed that the homozygous ms305 mutant was about the same to its wild type, in terms of plant type and flowering time, with the exceptions that its anthers could not be exposed and pollens were aborted. BSA analysis and CRISPR/Cas9 knockout (the target gene) experiments demonstrated that the mutated gene encodes a desiccation-related protein, with a base substitution (G > A) that caused an amino acid change at a conserved domain. In this project, we will further explore the MS305 gene regulatory network, its interacting proteins and potential DNA binding motif, as well as how MS305 gene could response to various abiotic stress conditions, by combining multiple strategies including transcriptome analysis, gene editing, and a number of biochemical experiments. In the end, we will reveal the molecular regulatory mechanism of MS305 gene, and its role in response to stress. In addition to the contribution on the molecular understanding of tassel development, our study will also provide a much needed genetic resource with potential of developing novel male sterile lines for hybrid seed production in maize.